Administrators have confirmed that money from the Ticketus deal was used by Rangers owner Craig Whyte to complete his takeover of the club.
The firm paid £24 million to secure the right to sell future season tickets.
According to a statement from the administrators, the cash was used by Whyte to pay the club's £18 million debt to Lloyds Banking Group when he completed his takeover last May.
David Whitehouse, joint administrator, said: "Since being appointed administrators last week there has been widespread concern raised with us, not least by Rangers supporters and season ticket holders, about the agreement between the club and Ticketus.
"Following information received, it is now apparent that the proceeds from the Ticketus arrangements amounted initially to a sum in the region of £20 million plus VAT.
"Subsequently, £18 million was transferred to the Lloyds Banking Group."
The statement from the administrators continued: "The application of the remainder of these proceeds is subject to further examination.
"We are now investigating all the circumstances surrounding both the purchase of the majority shareholding in Rangers Football Club plc and the flow of funds which stemmed from the transaction and were intended to fulfil the purchasers' obligations at the time of the sale.
"We cannot comment further on these matters while enquiries continue."
Whyte - who has revealed he will not continue as Rangers chairman post-restructuring - said of the Ticketus deal: "The arrangement with Ticketus - which was a three-season deal not four, as has been reported - was originally to provide additional working capital as had been the case previously under the old board.
"My corporate advisors came to me with the proposition that it was entirely possible, as well as highly beneficial, to negotiate a deal with Ticketus that would allow us to complete the takeover and maximise working capital for the club's day-to-day business.
"The Ticketus deal was by far the best way to protect the club given the circumstances in that they have no security over any assets.
"The only person at risk from the deal is me personally because I gave Ticketus personal and corporate guarantees underwriting their investment; the club and the fans are fully protected.
"In terms of exposure, I am personally on the line for £27.5 million in guarantees and cash. By any stretch of the imagination that is a very substantial commitment to the football club of which I have been a supporter since I was a boy and dearly wish to see through this crisis so that Rangers emerge as a financially fitter and stronger institution.
"I am the biggest stake-holder in Rangers and I face huge financial losses personally if the restructuring fails or is not allowed to proceed."